Construction of the Taum Sauk plant began in 1960 and operation began in 1963. The two original reversible pump-turbine units were each capable of generating 175 megawatts of power. They were upgraded in 1999 to units capable of 225 megawatts each. In 2005, the plant had to shut down when the upper reservoir suffered a catastrophic failure releasing 4 million cubic-meters of water in twelve minutes and sending a 20 foot crest of water down the Black River. The torrent of water roared into the Taum Sauk State park sweeping away the park superintendent's home and critically injuring his three small children.
The plant returned to service after a gap of four years. The rebuilt upper reservoir is now considered an engineering milestone, being the largest roller-compacted concrete dam in North America. To prevent another catastrophe, five back-up systems are now in place and nine cameras dot the reservoir's perimeter giving 24-hour surveillance to crews manning the facility around the clock.
Before the failure of the upper Reservoir visitors could usually drive to the top of Proffit Mountain and walk a ramp to an observation deck at the top of the reservoir. At the entrance gate there was also a museum highlighting the natural history of Missouri. The power plant was frequently visited by geology students because of a striking example of Precambrian/Cambrian unconformity in the rock layers exposed by the plant's construction.